src/HOL/Option.thy
author nipkow
Tue Apr 08 10:48:42 1997 +0200 (1997-04-08)
changeset 2919 953a47dc0519
parent 2019 b45d9f2042e0
child 4133 0a08c2b9b1ed
permissions -rw-r--r--
Dep. on Provers/nat_transitive
     1 (*  Title:      Option.thy
     2     ID:         $Id$
     3     Author:     Tobias Nipkow
     4     Copyright   1994  TU Muenchen
     5 
     6 Datatype 'a option
     7 *)
     8 
     9 Option = Arith +
    10 datatype 'a option = None | Some 'a
    11 end